1. Field of the Invention
Embodiments of the present invention relate to an injection blow molding system, apparatus and method for forming molded articles.
2. Description of the Related Art
Injection blow molding (IBM) is a technique used for creating various articles such as plastic bottles or containers. The IBM process is performed with an IBM machine that first injection molds a resin into a plurality of parisons of desired shapes and then blow molds the parisons into the final molded articles.
An injection station of the IBM machine typically includes a split parison mold assembly that defines a plurality of cavities within which the parisons are formed. In the injection molding stage of the IBM process, the parison-forming surfaces of the split parison mold are heated to and/or cooled to different temperatures via a plurality of water lines formed in the split parison mold near the parison-forming surfaces. The water lines may be supplied with water at different temperatures depending on the location of the water line relative to the neck or body of the parison being formed. For example, a body portion of the split parison mold may require heating to a temperature of about 210° F., while the neck portion of the split parison mold may require a relative cooling to a temperature of about 100° F. Typically, a plurality of individual thermolators are required to control the temperature of water supplied to the various water lines in the parison mold. However, even with such temperature control methods, maintaining precise temperatures within the split parison mold is difficult due to external temperature fluctuations and inherent temperature gradients that exist within the molds.
Similarly, a blow station of the IBM machine typically includes a split blow mold assembly that defines a plurality of cavities within which the parisons formed at the injection station are blow molded into final blow molded articles. In the blow molding stage of the IBM process, the article-forming surfaces of the blow mold are cooled to specific temperatures via a plurality of water lines formed in the split blow mold near the article-forming surfaces. For example, a body portion and a neck portion of the split blow mold may require cooling to a temperature of about 50° F. As with the injection station, maintaining precise temperatures within the split blow mold is difficult due to external temperature fluctuations and inherent temperature gradients that exist within the molds.
Thus, it would be desirable to have injection blow molding systems, apparatuses, and/or processes to allow for the split molds within the injection stations and the blow stations to maintain specific temperatures during formation of the parisons and/or the articles.